FeedLack Detects Missing Feedback in Web Applications

While usability methods such as user studies and inspections can reveal a wide range of problems, they do so for only a subset of an application's features and states. The authors present FeedLack, a tool that explores the full range of web applications' behaviors for one class of usability problems, namely that of missing feedback. It does this by enumerating control flow paths originating from user input, identifying paths that lack output-affecting code. FeedLack was applied to 330 applications; of the 129 that contained input handlers and did not contain syntax errors, 115 were successfully analyzed, resulting in 647 warnings.